DALLAS (AP) The NFL suspended star Dallas Cowboys running back Ezekiel Elliott for six games Friday, concluding after a yearlong investigation that the league's leading rusher injured his former girlfriend in three separate incidents last summer.

According to the letter Elliott received informing him of the suspension, the NFL believed he used "physical force" three times in a span of five days in a Columbus, Ohio, apartment last July resulting in injuries to Tiffany Thompson's face, neck, shoulders, arms, hands, wrists, hips and knees. She was his girlfriend at the time.

Prosecutors in Columbus decided nearly a year ago not to pursue the case in the city where Elliott starred for Ohio State. In announcing the suspension under the NFL's personal conduct policy, the league said its investigation was based on photographs, text messages and other electronic evidence. Commissioner Roger Goodell made his decision based on the findings and in consultation with four advisers, including Hall of Fame player Ken Houston.

Elliott posted a statement on his verified Twitter account Friday night, saying that he was "both surprised and disappointed" by the NFL's decision and that he strongly disagrees with the league's findings. He said he was "sincerely sorry" for the distraction and disruption that he has caused for the Cowboys and his family.

Elliott's ban means the Cowboys will have four players suspended when last year's NFC East champions start the season in a month - with the possibility of losing two more.

The 22-year-old Elliott has three days to appeal the ruling. While he made no direct reference to an appeal in his statement did, his legal team did in a separate statement.

"The NFL's findings are replete with factual inaccuracies and erroneous conclusions and it `cherry picks' so-called evidence to support its conclusion while ignoring other critical evidence," attorneys Frank Salzano and Scott Rosenblum said in a joint statement.

The attorneys said "a slew of additional credible and controverting evidence will come to light" through the appeal.

If Goodell's ruling stands, Elliott will go on the suspended list the first week of the regular season and be eligible to return to the active roster Oct. 23. His first possible game would be Week 8 at Washington.

The ruling requires Elliott to get an evaluation to determine whether he needs counseling or treatment, and to show proof that he is following up on any recommendations.

"I admit that I am far from perfect, but I plan to continue to work very hard, on and off the field, to mature and earn the great opportunity that I have been given," Elliott said in his statement.

Last September, the office of Columbus City Attorney Richard Pfeiffer cited conflicting and inconsistent information in the evidence in deciding against criminal charges. Pfeiffer's office declined comment Friday.

Peter Harvey, one of the advisers to Goodell, said the NFL had access to forensic electronic evidence that prosecutors didn't have, including proof that photographs were taken by Thompson the same day she alleged that she was injured by Elliott.

Harvey also said some of the explanations offered by Elliott's representatives, including that Thompson was injured in a fight with a woman or by falling down stairs, weren't supported by evidence.

Despite some conflicting testimonial evidence, the letter said that "there is no dispute that you and Ms. Thompson were together in the same location on the dates identified, and no evidence to suggest that anyone else could have caused these injuries."

Cowboys owner Jerry Jones had maintained he hadn't seen anything to indicate Elliott was guilty of domestic violence and he didn't think his star back would be suspended. Jones made the comments several times, including during festivities last weekend when he was inducted into the Pro Football Hall of Fame.

The ruling potentially could put Goodell and Jones, a strong supporter of the commissioner, at odds the same way Goodell clashed with New England owner Robert Kraft over last year's four-game suspension for quarterback Tom Brady over the "Deflategate" controversy.

The NFL revised its personal conduct policy in 2014 following sharp criticism of a case involving former Baltimore running back Ray Rice. The policy gave Goodell authority to suspend players for at least six games in domestic cases, with or without a conviction.

Elliott has had a string of off-field issues since the Cowboys made him the fourth overall pick in the 2016 draft. He was seen in a legal marijuana shop during the preseason in Seattle last year and was also involved in a bar fight in Dallas a week before training camp this year.

The NFL's letter to Elliott cited the Ohio case as well as an incident this past spring when Elliott was caught on video pulling down a woman's shirt while watching a St. Patrick's Day parade in Dallas. While not part of the decision on discipline, the league said that "inappropriate and disturbing" behavior reflected poorly on Elliott.

"When viewed together with the July incidents, it suggests a pattern of poor judgment and behavior for which effective intervention is necessary for your personal and professional welfare," NFL special counsel for conduct Todd Jones wrote.

An All-Pro as a rookie, Elliott finished with 1,631 yards rushing in helping the Cowboys to the best record in the NFC at 13-3 before a divisional playoff loss to Green Bay. He set rookie franchise records for yards, rushing touchdowns (15) and total touchdowns (16).

Three Dallas defensive ends will start the season with suspensions. Randy Gregory will miss at least the entire regular season for multiple violations of the NFL's substance-abuse policy. David Irving is out four games (performance-enhancing drugs) and Damontre Moore will sit two games (substance abuse).

Two more defensive players could face suspensions. Linebacker Damien Wilson faces aggravated assault charges in the Dallas suburb of Frisco over a dispute involving a parking space, and cornerback Nolan Carroll was arrested on a drunken-driving charge in Dallas.